Field of the Invention
The present invention relates to a data protection method, and more particularly, relates to a data protection method adapted to a rewritable non-volatile memory and a memory control circuit unit and a memory storage apparatus using the same.
Description of Related Art
The growth of digital cameras, mobile phones, and MP3 players has been rapid in recent years. Consequently, the consumers' demand for storage media has increased tremendously. In recent years, a rewritable non-volatile memory has become an important part of the electronic industries because the rewritable non-volatile memory is capable of providing features such as data non-volatility, low power consumption, small volume, non-mechanical structure and high read/write speed. For instance, a solid-state drive utilizing a flash memory as a storage media has been widely applied in a computer host as a main hard disk for enhancing access efficiency of computer.
The rewritable non-volatile memory module normally includes a plurality of physical erasing units. After being accessed or idle for a long time, the data stored in the physical erasing units may be lost or has error bits, and therefore the memory storage apparatus usually performs a refresh operation on the physical erasing units of the rewritable non-volatile memory module at predefined intervals, so as to ensure data accuracy. However, the current memory storage apparatus is unable to know the duration from the previous power-off to the present power-on, and therefore unable to determine whether to need to perform the refresh operation accurately according to time. How to obtain the off time from the previous power-off to the present power-on so as to determine accurately when to perform the refresh operation is one of the major concerns of artisans in the technical field.